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FFmpeg/libavcodec/vp3.c

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/*
*
* Copyright (C) 2003 the ffmpeg project
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* VP3 Video Decoder by Mike Melanson (melanson@pcisys.net)
*
*/
/**
* @file vp3.c
* On2 VP3 Video Decoder
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "dsputil.h"
#include "bswap.h"
#include "vp3data.h"
#define FRAGMENT_PIXELS 8
/*
* Debugging Variables
*
* Define one or more of the following compile-time variables to 1 to obtain
* elaborate information about certain aspects of the decoding process.
*
* KEYFRAMES_ONLY: set this to 1 to only see keyframes (VP3 slideshow mode)
* DEBUG_VP3: high-level decoding flow
* DEBUG_INIT: initialization parameters
* DEBUG_DEQUANTIZERS: display how the dequanization tables are built
* DEBUG_BLOCK_CODING: unpacking the superblock/macroblock/fragment coding
* DEBUG_MODES: unpacking the coding modes for individual fragments
* DEBUG_VECTORS: display the motion vectors
* DEBUG_TOKEN: display exhaustive information about each DCT token
* DEBUG_VLC: display the VLCs as they are extracted from the stream
* DEBUG_DC_PRED: display the process of reversing DC prediction
* DEBUG_IDCT: show every detail of the IDCT process
*/
#define KEYFRAMES_ONLY 0
#define DEBUG_VP3 0
#define DEBUG_INIT 0
#define DEBUG_DEQUANTIZERS 0
#define DEBUG_BLOCK_CODING 0
#define DEBUG_MODES 0
#define DEBUG_VECTORS 0
#define DEBUG_TOKEN 0
#define DEBUG_VLC 0
#define DEBUG_DC_PRED 0
#define DEBUG_IDCT 0
#if DEBUG_VP3
#define debug_vp3 printf
#else
static inline void debug_vp3(const char *format, ...) { }
#endif
#if DEBUG_INIT
#define debug_init printf
#else
static inline void debug_init(const char *format, ...) { }
#endif
#if DEBUG_DEQUANTIZERS
#define debug_dequantizers printf
#else
static inline void debug_dequantizers(const char *format, ...) { }
#endif
#if DEBUG_BLOCK_CODING
#define debug_block_coding printf
#else
static inline void debug_block_coding(const char *format, ...) { }
#endif
#if DEBUG_MODES
#define debug_modes printf
#else
static inline void debug_modes(const char *format, ...) { }
#endif
#if DEBUG_VECTORS
#define debug_vectors printf
#else
static inline void debug_vectors(const char *format, ...) { }
#endif
#if DEBUG_TOKEN
#define debug_token printf
#else
static inline void debug_token(const char *format, ...) { }
#endif
#if DEBUG_VLC
#define debug_vlc printf
#else
static inline void debug_vlc(const char *format, ...) { }
#endif
#if DEBUG_DC_PRED
#define debug_dc_pred printf
#else
static inline void debug_dc_pred(const char *format, ...) { }
#endif
#if DEBUG_IDCT
#define debug_idct printf
#else
static inline void debug_idct(const char *format, ...) { }
#endif
typedef struct Vp3Fragment {
DCTELEM coeffs[64];
int coding_method;
int coeff_count;
int last_coeff;
int motion_x;
int motion_y;
/* this indicates which ffmpeg put_pixels() function to use:
* 00b = no halfpel, 01b = x halfpel, 10b = y halfpel, 11b = both halfpel */
int motion_halfpel_index;
/* address of first pixel taking into account which plane the fragment
* lives on as well as the plane stride */
int first_pixel;
/* this is the macroblock that the fragment belongs to */
int macroblock;
} Vp3Fragment;
#define SB_NOT_CODED 0
#define SB_PARTIALLY_CODED 1
#define SB_FULLY_CODED 2
#define MODE_INTER_NO_MV 0
#define MODE_INTRA 1
#define MODE_INTER_PLUS_MV 2
#define MODE_INTER_LAST_MV 3
#define MODE_INTER_PRIOR_LAST 4
#define MODE_USING_GOLDEN 5
#define MODE_GOLDEN_MV 6
#define MODE_INTER_FOURMV 7
#define CODING_MODE_COUNT 8
/* special internal mode */
#define MODE_COPY 8
/* There are 6 preset schemes, plus a free-form scheme */
static int ModeAlphabet[7][CODING_MODE_COUNT] =
{
/* this is the custom scheme */
{ 0, 0, 0, 0, 0, 0, 0, 0 },
/* scheme 1: Last motion vector dominates */
{ MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
MODE_INTER_PLUS_MV, MODE_INTER_NO_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 2 */
{ MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
MODE_INTER_NO_MV, MODE_INTER_PLUS_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 3 */
{ MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
MODE_INTER_PRIOR_LAST, MODE_INTER_NO_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 4 */
{ MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
MODE_INTER_NO_MV, MODE_INTER_PRIOR_LAST,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 5: No motion vector dominates */
{ MODE_INTER_NO_MV, MODE_INTER_LAST_MV,
MODE_INTER_PRIOR_LAST, MODE_INTER_PLUS_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 6 */
{ MODE_INTER_NO_MV, MODE_USING_GOLDEN,
MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
MODE_INTER_PLUS_MV, MODE_INTRA,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
};
#define MIN_DEQUANT_VAL 2
typedef struct Vp3DecodeContext {
AVCodecContext *avctx;
int width, height;
AVFrame golden_frame;
AVFrame last_frame;
AVFrame current_frame;
int keyframe;
DSPContext dsp;
int quality_index;
int last_quality_index;
int superblock_count;
int superblock_width;
int superblock_height;
int y_superblock_width;
int y_superblock_height;
int c_superblock_width;
int c_superblock_height;
int u_superblock_start;
int v_superblock_start;
unsigned char *superblock_coding;
int macroblock_count;
int macroblock_width;
int macroblock_height;
int fragment_count;
int fragment_width;
int fragment_height;
Vp3Fragment *all_fragments;
int u_fragment_start;
int v_fragment_start;
/* this is a list of indices into the all_fragments array indicating
* which of the fragments are coded */
int *coded_fragment_list;
int coded_fragment_list_index;
int pixel_addresses_inited;
VLC dc_vlc[16];
VLC ac_vlc_1[16];
VLC ac_vlc_2[16];
VLC ac_vlc_3[16];
VLC ac_vlc_4[16];
int16_t intra_y_dequant[64];
int16_t intra_c_dequant[64];
int16_t inter_dequant[64];
/* This table contains superblock_count * 16 entries. Each set of 16
* numbers corresponds to the fragment indices 0..15 of the superblock.
* An entry will be -1 to indicate that no entry corresponds to that
* index. */
int *superblock_fragments;
/* This table contains superblock_count * 4 entries. Each set of 4
* numbers corresponds to the macroblock indices 0..3 of the superblock.
* An entry will be -1 to indicate that no entry corresponds to that
* index. */
int *superblock_macroblocks;
/* This table contains macroblock_count * 6 entries. Each set of 6
* numbers corresponds to the fragment indices 0..5 which comprise
* the macroblock (4 Y fragments and 2 C fragments). */
int *macroblock_fragments;
/* This is an array that indicates how a particular macroblock
* is coded. */
unsigned char *macroblock_coding;
int first_coded_y_fragment;
int first_coded_c_fragment;
int last_coded_y_fragment;
int last_coded_c_fragment;
} Vp3DecodeContext;
/************************************************************************
* VP3 specific functions
************************************************************************/
/*
* This function sets up all of the various blocks mappings:
* superblocks <-> fragments, macroblocks <-> fragments,
* superblocks <-> macroblocks
*
* Returns 0 is successful; returns 1 if *anything* went wrong.
*/
static int init_block_mapping(Vp3DecodeContext *s)
{
int i, j;
signed int hilbert_walk_y[16];
signed int hilbert_walk_c[16];
signed int hilbert_walk_mb[4];
int current_fragment = 0;
int current_width = 0;
int current_height = 0;
int right_edge = 0;
int bottom_edge = 0;
int superblock_row_inc = 0;
int *hilbert = NULL;
int mapping_index = 0;
int current_macroblock;
int c_fragment;
signed char travel_width[16] = {
1, 1, 0, -1,
0, 0, 1, 0,
1, 0, 1, 0,
0, -1, 0, 1
};
signed char travel_height[16] = {
0, 0, 1, 0,
1, 1, 0, -1,
0, 1, 0, -1,
-1, 0, -1, 0
};
signed char travel_width_mb[4] = {
1, 0, 1, 0
};
signed char travel_height_mb[4] = {
0, 1, 0, -1
};
debug_vp3(" vp3: initialize block mapping tables\n");
/* figure out hilbert pattern per these frame dimensions */
hilbert_walk_y[0] = 1;
hilbert_walk_y[1] = 1;
hilbert_walk_y[2] = s->fragment_width;
hilbert_walk_y[3] = -1;
hilbert_walk_y[4] = s->fragment_width;
hilbert_walk_y[5] = s->fragment_width;
hilbert_walk_y[6] = 1;
hilbert_walk_y[7] = -s->fragment_width;
hilbert_walk_y[8] = 1;
hilbert_walk_y[9] = s->fragment_width;
hilbert_walk_y[10] = 1;
hilbert_walk_y[11] = -s->fragment_width;
hilbert_walk_y[12] = -s->fragment_width;
hilbert_walk_y[13] = -1;
hilbert_walk_y[14] = -s->fragment_width;
hilbert_walk_y[15] = 1;
hilbert_walk_c[0] = 1;
hilbert_walk_c[1] = 1;
hilbert_walk_c[2] = s->fragment_width / 2;
hilbert_walk_c[3] = -1;
hilbert_walk_c[4] = s->fragment_width / 2;
hilbert_walk_c[5] = s->fragment_width / 2;
hilbert_walk_c[6] = 1;
hilbert_walk_c[7] = -s->fragment_width / 2;
hilbert_walk_c[8] = 1;
hilbert_walk_c[9] = s->fragment_width / 2;
hilbert_walk_c[10] = 1;
hilbert_walk_c[11] = -s->fragment_width / 2;
hilbert_walk_c[12] = -s->fragment_width / 2;
hilbert_walk_c[13] = -1;
hilbert_walk_c[14] = -s->fragment_width / 2;
hilbert_walk_c[15] = 1;
hilbert_walk_mb[0] = 1;
hilbert_walk_mb[1] = s->macroblock_width;
hilbert_walk_mb[2] = 1;
hilbert_walk_mb[3] = -s->macroblock_width;
/* iterate through each superblock (all planes) and map the fragments */
for (i = 0; i < s->superblock_count; i++) {
debug_init(" superblock %d (u starts @ %d, v starts @ %d)\n",
i, s->u_superblock_start, s->v_superblock_start);
/* time to re-assign the limits? */
if (i == 0) {
/* start of Y superblocks */
right_edge = s->fragment_width;
bottom_edge = s->fragment_height;
current_width = -1;
current_height = 0;
superblock_row_inc = 3 * s->fragment_width -
(s->y_superblock_width * 4 - s->fragment_width);
hilbert = hilbert_walk_y;
/* the first operation for this variable is to advance by 1 */
current_fragment = -1;
} else if (i == s->u_superblock_start) {
/* start of U superblocks */
right_edge = s->fragment_width / 2;
bottom_edge = s->fragment_height / 2;
current_width = -1;
current_height = 0;
superblock_row_inc = 3 * (s->fragment_width / 2) -
(s->c_superblock_width * 4 - s->fragment_width / 2);
hilbert = hilbert_walk_c;
/* the first operation for this variable is to advance by 1 */
current_fragment = s->u_fragment_start - 1;
} else if (i == s->v_superblock_start) {
/* start of V superblocks */
right_edge = s->fragment_width / 2;
bottom_edge = s->fragment_height / 2;
current_width = -1;
current_height = 0;
superblock_row_inc = 3 * (s->fragment_width / 2) -
(s->c_superblock_width * 4 - s->fragment_width / 2);
hilbert = hilbert_walk_c;
/* the first operation for this variable is to advance by 1 */
current_fragment = s->v_fragment_start - 1;
}
if (current_width >= right_edge - 1) {
/* reset width and move to next superblock row */
current_width = -1;
current_height += 4;
/* fragment is now at the start of a new superblock row */
current_fragment += superblock_row_inc;
}
/* iterate through all 16 fragments in a superblock */
for (j = 0; j < 16; j++) {
current_fragment += hilbert[j];
current_width += travel_width[j];
current_height += travel_height[j];
/* check if the fragment is in bounds */
if ((current_width < right_edge) &&
(current_height < bottom_edge)) {
s->superblock_fragments[mapping_index] = current_fragment;
debug_init(" mapping fragment %d to superblock %d, position %d (%d/%d x %d/%d)\n",
s->superblock_fragments[mapping_index], i, j,
current_width, right_edge, current_height, bottom_edge);
} else {
s->superblock_fragments[mapping_index] = -1;
debug_init(" superblock %d, position %d has no fragment (%d/%d x %d/%d)\n",
i, j,
current_width, right_edge, current_height, bottom_edge);
}
mapping_index++;
}
}
/* initialize the superblock <-> macroblock mapping; iterate through
* all of the Y plane superblocks to build this mapping */
right_edge = s->macroblock_width;
bottom_edge = s->macroblock_height;
current_width = -1;
current_height = 0;
superblock_row_inc = s->macroblock_width -
(s->y_superblock_width * 2 - s->macroblock_width);;
hilbert = hilbert_walk_mb;
mapping_index = 0;
current_macroblock = -1;
for (i = 0; i < s->u_superblock_start; i++) {
if (current_width >= right_edge - 1) {
/* reset width and move to next superblock row */
current_width = -1;
current_height += 2;
/* macroblock is now at the start of a new superblock row */
current_macroblock += superblock_row_inc;
}
/* iterate through each potential macroblock in the superblock */
for (j = 0; j < 4; j++) {
current_macroblock += hilbert_walk_mb[j];
current_width += travel_width_mb[j];
current_height += travel_height_mb[j];
/* check if the macroblock is in bounds */
if ((current_width < right_edge) &&
(current_height < bottom_edge)) {
s->superblock_macroblocks[mapping_index] = current_macroblock;
debug_init(" mapping macroblock %d to superblock %d, position %d (%d/%d x %d/%d)\n",
s->superblock_macroblocks[mapping_index], i, j,
current_width, right_edge, current_height, bottom_edge);
} else {
s->superblock_macroblocks[mapping_index] = -1;
debug_init(" superblock %d, position %d has no macroblock (%d/%d x %d/%d)\n",
i, j,
current_width, right_edge, current_height, bottom_edge);
}
mapping_index++;
}
}
/* initialize the macroblock <-> fragment mapping */
current_fragment = 0;
current_macroblock = 0;
mapping_index = 0;
for (i = 0; i < s->fragment_height; i += 2) {
for (j = 0; j < s->fragment_width; j += 2) {
debug_init(" macroblock %d contains fragments: ", current_macroblock);
s->all_fragments[current_fragment].macroblock = current_macroblock;
s->macroblock_fragments[mapping_index++] = current_fragment;
debug_init("%d ", current_fragment);
if (j + 1 < s->fragment_width) {
s->all_fragments[current_fragment + 1].macroblock = current_macroblock;
s->macroblock_fragments[mapping_index++] = current_fragment + 1;
debug_init("%d ", current_fragment + 1);
} else
s->macroblock_fragments[mapping_index++] = -1;
if (i + 1 < s->fragment_height) {
s->all_fragments[current_fragment + s->fragment_width].macroblock =
current_macroblock;
s->macroblock_fragments[mapping_index++] =
current_fragment + s->fragment_width;
debug_init("%d ", current_fragment + s->fragment_width);
} else
s->macroblock_fragments[mapping_index++] = -1;
if ((j + 1 < s->fragment_width) && (i + 1 < s->fragment_height)) {
s->all_fragments[current_fragment + s->fragment_width + 1].macroblock =
current_macroblock;
s->macroblock_fragments[mapping_index++] =
current_fragment + s->fragment_width + 1;
debug_init("%d ", current_fragment + s->fragment_width + 1);
} else
s->macroblock_fragments[mapping_index++] = -1;
/* C planes */
c_fragment = s->u_fragment_start +
(i * s->fragment_width / 4) + (j / 2);
s->all_fragments[c_fragment].macroblock = s->macroblock_count;
s->macroblock_fragments[mapping_index++] = c_fragment;
debug_init("%d ", c_fragment);
c_fragment = s->v_fragment_start +
(i * s->fragment_width / 4) + (j / 2);
s->all_fragments[c_fragment].macroblock = s->macroblock_count;
s->macroblock_fragments[mapping_index++] = c_fragment;
debug_init("%d ", c_fragment);
debug_init("\n");
if (j + 2 <= s->fragment_width)
current_fragment += 2;
else
current_fragment++;
current_macroblock++;
}
current_fragment += s->fragment_width;
}
return 0; /* successful path out */
}
/*
* This function unpacks a single token (which should be in the range 0..31)
* and returns a zero run (number of zero coefficients in current DCT matrix
* before next non-zero coefficient), the next DCT coefficient, and the
* number of consecutive, non-EOB'd DCT blocks to EOB.
*/
static void unpack_token(GetBitContext *gb, int token, int *zero_run,
DCTELEM *coeff, int *eob_run)
{
int sign;
*zero_run = 0;
*eob_run = 0;
*coeff = 0;
debug_token(" vp3 token %d: ", token);
switch (token) {
case 0:
debug_token("DCT_EOB_TOKEN, EOB next block\n");
*eob_run = 1;
break;
case 1:
debug_token("DCT_EOB_PAIR_TOKEN, EOB next 2 blocks\n");
*eob_run = 2;
break;
case 2:
debug_token("DCT_EOB_TRIPLE_TOKEN, EOB next 3 blocks\n");
*eob_run = 3;
break;
case 3:
debug_token("DCT_REPEAT_RUN_TOKEN, ");
*eob_run = get_bits(gb, 2) + 4;
debug_token("EOB the next %d blocks\n", *eob_run);
break;
case 4:
debug_token("DCT_REPEAT_RUN2_TOKEN, ");
*eob_run = get_bits(gb, 3) + 8;
debug_token("EOB the next %d blocks\n", *eob_run);
break;
case 5:
debug_token("DCT_REPEAT_RUN3_TOKEN, ");
*eob_run = get_bits(gb, 4) + 16;
debug_token("EOB the next %d blocks\n", *eob_run);
break;
case 6:
debug_token("DCT_REPEAT_RUN4_TOKEN, ");
*eob_run = get_bits(gb, 12);
debug_token("EOB the next %d blocks\n", *eob_run);
break;
case 7:
debug_token("DCT_SHORT_ZRL_TOKEN, ");
/* note that this token actually indicates that (3 extra bits) + 1 0s
* should be output; this case specifies a run of (3 EBs) 0s and a
* coefficient of 0. */
*zero_run = get_bits(gb, 3);
*coeff = 0;
debug_token("skip the next %d positions in output matrix\n", *zero_run + 1);
break;
case 8:
debug_token("DCT_ZRL_TOKEN, ");
/* note that this token actually indicates that (6 extra bits) + 1 0s
* should be output; this case specifies a run of (6 EBs) 0s and a
* coefficient of 0. */
*zero_run = get_bits(gb, 6);
*coeff = 0;
debug_token("skip the next %d positions in output matrix\n", *zero_run + 1);
break;
case 9:
debug_token("ONE_TOKEN, output 1\n");
*coeff = 1;
break;
case 10:
debug_token("MINUS_ONE_TOKEN, output -1\n");
*coeff = -1;
break;
case 11:
debug_token("TWO_TOKEN, output 2\n");
*coeff = 2;
break;
case 12:
debug_token("MINUS_TWO_TOKEN, output -2\n");
*coeff = -2;
break;
case 13:
case 14:
case 15:
case 16:
debug_token("LOW_VAL_TOKENS, ");
if (get_bits(gb, 1))
*coeff = -(3 + (token - 13));
else
*coeff = 3 + (token - 13);
debug_token("output %d\n", *coeff);
break;
case 17:
debug_token("DCT_VAL_CATEGORY3, ");
sign = get_bits(gb, 1);
*coeff = 7 + get_bits(gb, 1);
if (sign)
*coeff = -(*coeff);
debug_token("output %d\n", *coeff);
break;
case 18:
debug_token("DCT_VAL_CATEGORY4, ");
sign = get_bits(gb, 1);
*coeff = 9 + get_bits(gb, 2);
if (sign)
*coeff = -(*coeff);
debug_token("output %d\n", *coeff);
break;
case 19:
debug_token("DCT_VAL_CATEGORY5, ");
sign = get_bits(gb, 1);
*coeff = 13 + get_bits(gb, 3);
if (sign)
*coeff = -(*coeff);
debug_token("output %d\n", *coeff);
break;
case 20:
debug_token("DCT_VAL_CATEGORY6, ");
sign = get_bits(gb, 1);
*coeff = 21 + get_bits(gb, 4);
if (sign)
*coeff = -(*coeff);
debug_token("output %d\n", *coeff);
break;
case 21:
debug_token("DCT_VAL_CATEGORY7, ");
sign = get_bits(gb, 1);
*coeff = 37 + get_bits(gb, 5);
if (sign)
*coeff = -(*coeff);
debug_token("output %d\n", *coeff);
break;
case 22:
debug_token("DCT_VAL_CATEGORY8, ");
sign = get_bits(gb, 1);
*coeff = 69 + get_bits(gb, 9);
if (sign)
*coeff = -(*coeff);
debug_token("output %d\n", *coeff);
break;
case 23:
case 24:
case 25:
case 26:
case 27:
debug_token("DCT_RUN_CATEGORY1, ");
*zero_run = token - 22;
if (get_bits(gb, 1))
*coeff = -1;
else
*coeff = 1;
debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
break;
case 28:
debug_token("DCT_RUN_CATEGORY1B, ");
if (get_bits(gb, 1))
*coeff = -1;
else
*coeff = 1;
*zero_run = 6 + get_bits(gb, 2);
debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
break;
case 29:
debug_token("DCT_RUN_CATEGORY1C, ");
if (get_bits(gb, 1))
*coeff = -1;
else
*coeff = 1;
*zero_run = 10 + get_bits(gb, 3);
debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
break;
case 30:
debug_token("DCT_RUN_CATEGORY2, ");
sign = get_bits(gb, 1);
*coeff = 2 + get_bits(gb, 1);
if (sign)
*coeff = -(*coeff);
*zero_run = 1;
debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
break;
case 31:
debug_token("DCT_RUN_CATEGORY2, ");
sign = get_bits(gb, 1);
*coeff = 2 + get_bits(gb, 1);
if (sign)
*coeff = -(*coeff);
*zero_run = 2 + get_bits(gb, 1);
debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
break;
default:
printf (" vp3: help! Got a bad token: %d > 31\n", token);
break;
}
}
/*
* This function wipes out all of the fragment data.
*/
static void init_frame(Vp3DecodeContext *s, GetBitContext *gb)
{
int i;
/* zero out all of the fragment information */
s->coded_fragment_list_index = 0;
for (i = 0; i < s->fragment_count; i++) {
memset(s->all_fragments[i].coeffs, 0, 64 * sizeof(DCTELEM));
s->all_fragments[i].coeff_count = 0;
s->all_fragments[i].last_coeff = 0;
}
}
/*
* This function sets of the dequantization tables used for a particular
* frame.
*/
static void init_dequantizer(Vp3DecodeContext *s)
{
int quality_scale = vp31_quality_threshold[s->quality_index];
int dc_scale_factor = vp31_dc_scale_factor[s->quality_index];
int i, j;
debug_vp3(" vp3: initializing dequantization tables\n");
/*
* Scale dequantizers:
*
* quantizer * sf
* --------------
* 100
*
* where sf = dc_scale_factor for DC quantizer
* or quality_scale for AC quantizer
*
* Then, saturate the result to a lower limit of MIN_DEQUANT_VAL.
*/
#define SCALER 1
/* scale DC quantizers */
s->intra_y_dequant[0] = vp31_intra_y_dequant[0] * dc_scale_factor / 100;
if (s->intra_y_dequant[0] < MIN_DEQUANT_VAL * 2)
s->intra_y_dequant[0] = MIN_DEQUANT_VAL * 2;
s->intra_y_dequant[0] *= SCALER;
s->intra_c_dequant[0] = vp31_intra_c_dequant[0] * dc_scale_factor / 100;
if (s->intra_c_dequant[0] < MIN_DEQUANT_VAL * 2)
s->intra_c_dequant[0] = MIN_DEQUANT_VAL * 2;
s->intra_c_dequant[0] *= SCALER;
s->inter_dequant[0] = vp31_inter_dequant[0] * dc_scale_factor / 100;
if (s->inter_dequant[0] < MIN_DEQUANT_VAL * 4)
s->inter_dequant[0] = MIN_DEQUANT_VAL * 4;
s->inter_dequant[0] *= SCALER;
/* scale AC quantizers, zigzag at the same time in preparation for
* the dequantization phase */
for (i = 1; i < 64; i++) {
j = zigzag_index[i];
s->intra_y_dequant[j] = vp31_intra_y_dequant[i] * quality_scale / 100;
if (s->intra_y_dequant[j] < MIN_DEQUANT_VAL)
s->intra_y_dequant[j] = MIN_DEQUANT_VAL;
s->intra_y_dequant[j] *= SCALER;
s->intra_c_dequant[j] = vp31_intra_c_dequant[i] * quality_scale / 100;
if (s->intra_c_dequant[j] < MIN_DEQUANT_VAL)
s->intra_c_dequant[j] = MIN_DEQUANT_VAL;
s->intra_c_dequant[j] *= SCALER;
s->inter_dequant[j] = vp31_inter_dequant[i] * quality_scale / 100;
if (s->inter_dequant[j] < MIN_DEQUANT_VAL * 2)
s->inter_dequant[j] = MIN_DEQUANT_VAL * 2;
s->inter_dequant[j] *= SCALER;
}
/* print debug information as requested */
debug_dequantizers("intra Y dequantizers:\n");
for (i = 0; i < 8; i++) {
for (j = i * 8; j < i * 8 + 8; j++) {
debug_dequantizers(" %4d,", s->intra_y_dequant[j]);
}
debug_dequantizers("\n");
}
debug_dequantizers("\n");
debug_dequantizers("intra C dequantizers:\n");
for (i = 0; i < 8; i++) {
for (j = i * 8; j < i * 8 + 8; j++) {
debug_dequantizers(" %4d,", s->intra_c_dequant[j]);
}
debug_dequantizers("\n");
}
debug_dequantizers("\n");
debug_dequantizers("interframe dequantizers:\n");
for (i = 0; i < 8; i++) {
for (j = i * 8; j < i * 8 + 8; j++) {
debug_dequantizers(" %4d,", s->inter_dequant[j]);
}
debug_dequantizers("\n");
}
debug_dequantizers("\n");
}
/*
* This function is used to fetch runs of 1s or 0s from the bitstream for
* use in determining which superblocks are fully and partially coded.
*
* Codeword RunLength
* 0 1
* 10x 2-3
* 110x 4-5
* 1110xx 6-9
* 11110xxx 10-17
* 111110xxxx 18-33
* 111111xxxxxxxxxxxx 34-4129
*/
static int get_superblock_run_length(GetBitContext *gb)
{
if (get_bits(gb, 1) == 0)
return 1;
else if (get_bits(gb, 1) == 0)
return (2 + get_bits(gb, 1));
else if (get_bits(gb, 1) == 0)
return (4 + get_bits(gb, 1));
else if (get_bits(gb, 1) == 0)
return (6 + get_bits(gb, 2));
else if (get_bits(gb, 1) == 0)
return (10 + get_bits(gb, 3));
else if (get_bits(gb, 1) == 0)
return (18 + get_bits(gb, 4));
else
return (34 + get_bits(gb, 12));
}
/*
* This function is used to fetch runs of 1s or 0s from the bitstream for
* use in determining which particular fragments are coded.
*
* Codeword RunLength
* 0x 1-2
* 10x 3-4
* 110x 5-6
* 1110xx 7-10
* 11110xx 11-14
* 11111xxxx 15-30
*/
static int get_fragment_run_length(GetBitContext *gb)
{
if (get_bits(gb, 1) == 0)
return (1 + get_bits(gb, 1));
else if (get_bits(gb, 1) == 0)
return (3 + get_bits(gb, 1));
else if (get_bits(gb, 1) == 0)
return (5 + get_bits(gb, 1));
else if (get_bits(gb, 1) == 0)
return (7 + get_bits(gb, 2));
else if (get_bits(gb, 1) == 0)
return (11 + get_bits(gb, 2));
else
return (15 + get_bits(gb, 4));
}
/*
* This function decodes a VLC from the bitstream and returns a number
* that ranges from 0..7. The number indicates which of the 8 coding
* modes to use.
*
* VLC Number
* 0 0
* 10 1
* 110 2
* 1110 3
* 11110 4
* 111110 5
* 1111110 6
* 1111111 7
*
*/
static int get_mode_code(GetBitContext *gb)
{
if (get_bits(gb, 1) == 0)
return 0;
else if (get_bits(gb, 1) == 0)
return 1;
else if (get_bits(gb, 1) == 0)
return 2;
else if (get_bits(gb, 1) == 0)
return 3;
else if (get_bits(gb, 1) == 0)
return 4;
else if (get_bits(gb, 1) == 0)
return 5;
else if (get_bits(gb, 1) == 0)
return 6;
else
return 7;
}
/*
* This function extracts a motion vector from the bitstream using a VLC
* scheme. 3 bits are fetched from the bitstream and 1 of 8 actions is
* taken depending on the value on those 3 bits:
*
* 0: return 0
* 1: return 1
* 2: return -1
* 3: if (next bit is 1) return -2, else return 2
* 4: if (next bit is 1) return -3, else return 3
* 5: return 4 + (next 2 bits), next bit is sign
* 6: return 8 + (next 3 bits), next bit is sign
* 7: return 16 + (next 4 bits), next bit is sign
*/
static int get_motion_vector_vlc(GetBitContext *gb)
{
int bits;
bits = get_bits(gb, 3);
switch(bits) {
case 0:
bits = 0;
break;
case 1:
bits = 1;
break;
case 2:
bits = -1;
break;
case 3:
if (get_bits(gb, 1) == 0)
bits = 2;
else
bits = -2;
break;
case 4:
if (get_bits(gb, 1) == 0)
bits = 3;
else
bits = -3;
break;
case 5:
bits = 4 + get_bits(gb, 2);
if (get_bits(gb, 1) == 1)
bits = -bits;
break;
case 6:
bits = 8 + get_bits(gb, 3);
if (get_bits(gb, 1) == 1)
bits = -bits;
break;
case 7:
bits = 16 + get_bits(gb, 4);
if (get_bits(gb, 1) == 1)
bits = -bits;
break;
}
return bits;
}
/*
* This function fetches a 5-bit number from the stream followed by
* a sign and calls it a motion vector.
*/
static int get_motion_vector_fixed(GetBitContext *gb)
{
int bits;
bits = get_bits(gb, 5);
if (get_bits(gb, 1) == 1)
bits = -bits;
return bits;
}
/*
* This function unpacks all of the superblock/macroblock/fragment coding
* information from the bitstream.
*/
static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
{
int bit = 0;
int current_superblock = 0;
int current_run = 0;
int decode_fully_flags = 0;
int decode_partial_blocks = 0;
int first_c_fragment_seen;
int i, j;
int current_fragment;
debug_vp3(" vp3: unpacking superblock coding\n");
if (s->keyframe) {
debug_vp3(" keyframe-- all superblocks are fully coded\n");
memset(s->superblock_coding, SB_FULLY_CODED, s->superblock_count);
} else {
/* unpack the list of partially-coded superblocks */
bit = get_bits(gb, 1);
/* toggle the bit because as soon as the first run length is
* fetched the bit will be toggled again */
bit ^= 1;
while (current_superblock < s->superblock_count) {
if (current_run == 0) {
bit ^= 1;
current_run = get_superblock_run_length(gb);
debug_block_coding(" setting superblocks %d..%d to %s\n",
current_superblock,
current_superblock + current_run - 1,
(bit) ? "partially coded" : "not coded");
/* if any of the superblocks are not partially coded, flag
* a boolean to decode the list of fully-coded superblocks */
if (bit == 0)
decode_fully_flags = 1;
} else {
/* make a note of the fact that there are partially coded
* superblocks */
decode_partial_blocks = 1;
}
s->superblock_coding[current_superblock++] =
(bit) ? SB_PARTIALLY_CODED : SB_NOT_CODED;
current_run--;
}
/* unpack the list of fully coded superblocks if any of the blocks were
* not marked as partially coded in the previous step */
if (decode_fully_flags) {
current_superblock = 0;
current_run = 0;
bit = get_bits(gb, 1);
/* toggle the bit because as soon as the first run length is
* fetched the bit will be toggled again */
bit ^= 1;
while (current_superblock < s->superblock_count) {
/* skip any superblocks already marked as partially coded */
if (s->superblock_coding[current_superblock] == SB_NOT_CODED) {
if (current_run == 0) {
bit ^= 1;
current_run = get_superblock_run_length(gb);
}
debug_block_coding(" setting superblock %d to %s\n",
current_superblock,
(bit) ? "fully coded" : "not coded");
s->superblock_coding[current_superblock] =
(bit) ? SB_FULLY_CODED : SB_NOT_CODED;
current_run--;
}
current_superblock++;
}
}
/* if there were partial blocks, initialize bitstream for
* unpacking fragment codings */
if (decode_partial_blocks) {
current_run = 0;
bit = get_bits(gb, 1);
/* toggle the bit because as soon as the first run length is
* fetched the bit will be toggled again */
bit ^= 1;
}
}
/* figure out which fragments are coded; iterate through each
* superblock (all planes) */
s->coded_fragment_list_index = 0;
s->first_coded_y_fragment = s->first_coded_c_fragment = 0;
s->last_coded_y_fragment = s->last_coded_c_fragment = -1;
first_c_fragment_seen = 0;
memset(s->macroblock_coding, MODE_COPY, s->macroblock_count);
for (i = 0; i < s->superblock_count; i++) {
/* iterate through all 16 fragments in a superblock */
for (j = 0; j < 16; j++) {
/* if the fragment is in bounds, check its coding status */
current_fragment = s->superblock_fragments[i * 16 + j];
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_superblocks(): bad fragment number (%d >= %d)\n",
current_fragment, s->fragment_count);
return 1;
}
if (current_fragment != -1) {
if (s->superblock_coding[i] == SB_NOT_CODED) {
/* copy all the fragments from the prior frame */
s->all_fragments[current_fragment].coding_method =
MODE_COPY;
} else if (s->superblock_coding[i] == SB_PARTIALLY_CODED) {
/* fragment may or may not be coded; this is the case
* that cares about the fragment coding runs */
if (current_run == 0) {
bit ^= 1;
current_run = get_fragment_run_length(gb);
}
if (bit) {
/* default mode; actual mode will be decoded in
* the next phase */
s->all_fragments[current_fragment].coding_method =
MODE_INTER_NO_MV;
s->coded_fragment_list[s->coded_fragment_list_index] =
current_fragment;
if ((current_fragment >= s->u_fragment_start) &&
(s->last_coded_y_fragment == -1) &&
(!first_c_fragment_seen)) {
s->first_coded_c_fragment = s->coded_fragment_list_index;
s->last_coded_y_fragment = s->first_coded_c_fragment - 1;
first_c_fragment_seen = 1;
}
s->coded_fragment_list_index++;
s->macroblock_coding[s->all_fragments[current_fragment].macroblock] = MODE_INTER_NO_MV;
debug_block_coding(" superblock %d is partially coded, fragment %d is coded\n",
i, current_fragment);
} else {
/* not coded; copy this fragment from the prior frame */
s->all_fragments[current_fragment].coding_method =
MODE_COPY;
debug_block_coding(" superblock %d is partially coded, fragment %d is not coded\n",
i, current_fragment);
}
current_run--;
} else {
/* fragments are fully coded in this superblock; actual
* coding will be determined in next step */
s->all_fragments[current_fragment].coding_method =
MODE_INTER_NO_MV;
s->coded_fragment_list[s->coded_fragment_list_index] =
current_fragment;
if ((current_fragment >= s->u_fragment_start) &&
(s->last_coded_y_fragment == -1) &&
(!first_c_fragment_seen)) {
s->first_coded_c_fragment = s->coded_fragment_list_index;
s->last_coded_y_fragment = s->first_coded_c_fragment - 1;
first_c_fragment_seen = 1;
}
s->coded_fragment_list_index++;
s->macroblock_coding[s->all_fragments[current_fragment].macroblock] = MODE_INTER_NO_MV;
debug_block_coding(" superblock %d is fully coded, fragment %d is coded\n",
i, current_fragment);
}
}
}
}
if (!first_c_fragment_seen)
/* only Y fragments coded in this frame */
s->last_coded_y_fragment = s->coded_fragment_list_index - 1;
else
/* end the list of coded fragments */
s->last_coded_c_fragment = s->coded_fragment_list_index - 1;
debug_block_coding(" %d total coded fragments, y: %d -> %d, c: %d -> %d\n",
s->coded_fragment_list_index,
s->first_coded_y_fragment,
s->last_coded_y_fragment,
s->first_coded_c_fragment,
s->last_coded_c_fragment);
return 0;
}
/*
* This function unpacks all the coding mode data for individual macroblocks
* from the bitstream.
*/
static int unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
{
int i, j, k;
int scheme;
int current_macroblock;
int current_fragment;
int coding_mode;
debug_vp3(" vp3: unpacking encoding modes\n");
if (s->keyframe) {
debug_vp3(" keyframe-- all blocks are coded as INTRA\n");
for (i = 0; i < s->fragment_count; i++)
s->all_fragments[i].coding_method = MODE_INTRA;
} else {
/* fetch the mode coding scheme for this frame */
scheme = get_bits(gb, 3);
debug_modes(" using mode alphabet %d\n", scheme);
/* is it a custom coding scheme? */
if (scheme == 0) {
debug_modes(" custom mode alphabet ahead:\n");
for (i = 0; i < 8; i++)
ModeAlphabet[scheme][get_bits(gb, 3)] = i;
}
for (i = 0; i < 8; i++)
debug_modes(" mode[%d][%d] = %d\n", scheme, i,
ModeAlphabet[scheme][i]);
/* iterate through all of the macroblocks that contain 1 or more
* coded fragments */
for (i = 0; i < s->u_superblock_start; i++) {
for (j = 0; j < 4; j++) {
current_macroblock = s->superblock_macroblocks[i * 4 + j];
if ((current_macroblock == -1) ||
(s->macroblock_coding[current_macroblock] == MODE_COPY))
continue;
if (current_macroblock >= s->macroblock_count) {
printf (" vp3:unpack_modes(): bad macroblock number (%d >= %d)\n",
current_macroblock, s->macroblock_count);
return 1;
}
/* mode 7 means get 3 bits for each coding mode */
if (scheme == 7)
coding_mode = get_bits(gb, 3);
else
coding_mode = ModeAlphabet[scheme][get_mode_code(gb)];
s->macroblock_coding[current_macroblock] = coding_mode;
for (k = 0; k < 6; k++) {
current_fragment =
s->macroblock_fragments[current_macroblock * 6 + k];
if (current_fragment == -1)
continue;
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_modes(): bad fragment number (%d >= %d)\n",
current_fragment, s->fragment_count);
return 1;
}
if (s->all_fragments[current_fragment].coding_method !=
MODE_COPY)
s->all_fragments[current_fragment].coding_method =
coding_mode;
}
debug_modes(" coding method for macroblock starting @ fragment %d = %d\n",
s->macroblock_fragments[current_macroblock * 6], coding_mode);
}
}
}
return 0;
}
/*
* This function adjusts the components of a motion vector for the halfpel
* motion grid. c_plane indicates whether the vector applies to the U or V
* plane. The function returns the halfpel function index to be used in
* ffmpeg's put_pixels[]() array of functions.
*/
static inline int adjust_vector(int *x, int *y, int c_plane)
{
int motion_halfpel_index = 0;
int x_halfpel;
int y_halfpel;
if (!c_plane) {
x_halfpel = *x & 1;
motion_halfpel_index |= x_halfpel;
if (*x >= 0)
*x >>= 1;
else
*x = -( (-(*x) >> 1) + x_halfpel);
y_halfpel = *y & 1;
motion_halfpel_index |= (y_halfpel << 1);
if (*y >= 0)
*y >>= 1;
else
*y = -( (-(*y) >> 1) + y_halfpel);
} else {
x_halfpel = ((*x & 0x03) != 0);
motion_halfpel_index |= x_halfpel;
if (*x >= 0)
*x >>= 2;
else
*x = -( (-(*x) >> 2) + x_halfpel);
y_halfpel = ((*y & 0x03) != 0);
motion_halfpel_index |= (y_halfpel << 1);
if (*y >= 0)
*y >>= 2;
else
*y = -( (-(*y) >> 2) + y_halfpel);
}
return motion_halfpel_index;
}
/*
* This function unpacks all the motion vectors for the individual
* macroblocks from the bitstream.
*/
static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
{
int i, j, k;
int coding_mode;
int motion_x[6];
int motion_y[6];
int last_motion_x = 0;
int last_motion_y = 0;
int prior_last_motion_x = 0;
int prior_last_motion_y = 0;
int current_macroblock;
int current_fragment;
debug_vp3(" vp3: unpacking motion vectors\n");
if (s->keyframe) {
debug_vp3(" keyframe-- there are no motion vectors\n");
} else {
memset(motion_x, 0, 6 * sizeof(int));
memset(motion_y, 0, 6 * sizeof(int));
/* coding mode 0 is the VLC scheme; 1 is the fixed code scheme */
coding_mode = get_bits(gb, 1);
debug_vectors(" using %s scheme for unpacking motion vectors\n",
(coding_mode == 0) ? "VLC" : "fixed-length");
/* iterate through all of the macroblocks that contain 1 or more
* coded fragments */
for (i = 0; i < s->u_superblock_start; i++) {
for (j = 0; j < 4; j++) {
current_macroblock = s->superblock_macroblocks[i * 4 + j];
if ((current_macroblock == -1) ||
(s->macroblock_coding[current_macroblock] == MODE_COPY))
continue;
if (current_macroblock >= s->macroblock_count) {
printf (" vp3:unpack_vectors(): bad macroblock number (%d >= %d)\n",
current_macroblock, s->macroblock_count);
return 1;
}
current_fragment = s->macroblock_fragments[current_macroblock * 6];
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_vectors(): bad fragment number (%d >= %d\n",
current_fragment, s->fragment_count);
return 1;
}
switch (s->macroblock_coding[current_macroblock]) {
case MODE_INTER_PLUS_MV:
case MODE_GOLDEN_MV:
/* all 6 fragments use the same motion vector */
if (coding_mode == 0) {
motion_x[0] = get_motion_vector_vlc(gb);
motion_y[0] = get_motion_vector_vlc(gb);
} else {
motion_x[0] = get_motion_vector_fixed(gb);
motion_y[0] = get_motion_vector_fixed(gb);
}
for (k = 1; k < 6; k++) {
motion_x[k] = motion_x[0];
motion_y[k] = motion_y[0];
}
/* vector maintenance, only on MODE_INTER_PLUS_MV */
if (s->all_fragments[current_fragment].coding_method ==
MODE_INTER_PLUS_MV) {
prior_last_motion_x = last_motion_x;
prior_last_motion_y = last_motion_y;
last_motion_x = motion_x[0];
last_motion_y = motion_y[0];
}
break;
case MODE_INTER_FOURMV:
/* fetch 4 vectors from the bitstream, one for each
* Y fragment, then average for the C fragment vectors */
motion_x[4] = motion_y[4] = 0;
for (k = 0; k < 4; k++) {
if (coding_mode == 0) {
motion_x[k] = get_motion_vector_vlc(gb);
motion_y[k] = get_motion_vector_vlc(gb);
} else {
motion_x[k] = get_motion_vector_fixed(gb);
motion_y[k] = get_motion_vector_fixed(gb);
}
motion_x[4] += motion_x[k];
motion_y[4] += motion_y[k];
}
if (motion_x[4] >= 0)
motion_x[4] = (motion_x[4] + 2) / 4;
else
motion_x[4] = (motion_x[4] - 2) / 4;
motion_x[5] = motion_x[4];
if (motion_y[4] >= 0)
motion_y[4] = (motion_y[4] + 2) / 4;
else
motion_y[4] = (motion_y[4] - 2) / 4;
motion_y[5] = motion_y[4];
/* vector maintenance; vector[3] is treated as the
* last vector in this case */
prior_last_motion_x = last_motion_x;
prior_last_motion_y = last_motion_y;
last_motion_x = motion_x[3];
last_motion_y = motion_y[3];
break;
case MODE_INTER_LAST_MV:
/* all 6 fragments use the last motion vector */
motion_x[0] = last_motion_x;
motion_y[0] = last_motion_y;
for (k = 1; k < 6; k++) {
motion_x[k] = motion_x[0];
motion_y[k] = motion_y[0];
}
/* no vector maintenance (last vector remains the
* last vector) */
break;
case MODE_INTER_PRIOR_LAST:
/* all 6 fragments use the motion vector prior to the
* last motion vector */
motion_x[0] = prior_last_motion_x;
motion_y[0] = prior_last_motion_y;
for (k = 1; k < 6; k++) {
motion_x[k] = motion_x[0];
motion_y[k] = motion_y[0];
}
/* vector maintenance */
prior_last_motion_x = last_motion_x;
prior_last_motion_y = last_motion_y;
last_motion_x = motion_x[0];
last_motion_y = motion_y[0];
break;
default:
/* covers intra, inter without MV, golden without MV */
memset(motion_x, 0, 6 * sizeof(int));
memset(motion_y, 0, 6 * sizeof(int));
/* no vector maintenance */
break;
}
/* assign the motion vectors to the correct fragments */
debug_vectors(" vectors for macroblock starting @ fragment %d (coding method %d):\n",
current_fragment,
s->all_fragments[current_fragment].coding_method);
for (k = 0; k < 6; k++) {
current_fragment =
s->macroblock_fragments[current_macroblock * 6 + k];
if (current_fragment == -1)
continue;
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_vectors(): bad fragment number (%d >= %d)\n",
current_fragment, s->fragment_count);
return 1;
}
s->all_fragments[current_fragment].motion_halfpel_index =
adjust_vector(&motion_x[k], &motion_y[k],
((k == 4) || (k == 5)));
s->all_fragments[current_fragment].motion_x = motion_x[k];
s->all_fragments[current_fragment].motion_y = motion_y[k];
debug_vectors(" vector %d: fragment %d = (%d, %d), index %d\n",
k, current_fragment, motion_x[k], motion_y[k],
s->all_fragments[current_fragment].motion_halfpel_index);
}
}
}
}
return 0;
}
/*
* This function is called by unpack_dct_coeffs() to extract the VLCs from
* the bitstream. The VLCs encode tokens which are used to unpack DCT
* data. This function unpacks all the VLCs for either the Y plane or both
* C planes, and is called for DC coefficients or different AC coefficient
* levels (since different coefficient types require different VLC tables.
*
* This function returns a residual eob run. E.g, if a particular token gave
* instructions to EOB the next 5 fragments and there were only 2 fragments
* left in the current fragment range, 3 would be returned so that it could
* be passed into the next call to this same function.
*/
static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
VLC *table, int coeff_index,
int first_fragment, int last_fragment,
int eob_run)
{
int i;
int token;
int zero_run;
DCTELEM coeff;
Vp3Fragment *fragment;
if ((first_fragment >= s->fragment_count) ||
(last_fragment >= s->fragment_count)) {
printf (" vp3:unpack_vlcs(): bad fragment number (%d -> %d ?)\n",
first_fragment, last_fragment);
return 0;
}
for (i = first_fragment; i <= last_fragment; i++) {
fragment = &s->all_fragments[s->coded_fragment_list[i]];
if (fragment->coeff_count > coeff_index)
continue;
if (!eob_run) {
/* decode a VLC into a token */
token = get_vlc2(gb, table->table, 5, 3);
debug_vlc(" token = %2d, ", token);
/* use the token to get a zero run, a coefficient, and an eob run */
unpack_token(gb, token, &zero_run, &coeff, &eob_run);
}
if (!eob_run) {
fragment->coeff_count += zero_run;
if (fragment->coeff_count < 64)
fragment->coeffs[fragment->coeff_count++] = coeff;
debug_vlc(" fragment %d coeff = %d\n",
s->coded_fragment_list[i], fragment->coeffs[coeff_index]);
} else {
fragment->last_coeff = fragment->coeff_count;
fragment->coeff_count = 64;
debug_vlc(" fragment %d eob with %d coefficients\n",
s->coded_fragment_list[i], fragment->last_coeff);
eob_run--;
}
}
return eob_run;
}
/*
* This function unpacks all of the DCT coefficient data from the
* bitstream.
*/
static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
{
int i;
int dc_y_table;
int dc_c_table;
int ac_y_table;
int ac_c_table;
int residual_eob_run = 0;
/* fetch the DC table indices */
dc_y_table = get_bits(gb, 4);
dc_c_table = get_bits(gb, 4);
/* unpack the Y plane DC coefficients */
debug_vp3(" vp3: unpacking Y plane DC coefficients using table %d\n",
dc_y_table);
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
/* unpack the C plane DC coefficients */
debug_vp3(" vp3: unpacking C plane DC coefficients using table %d\n",
dc_c_table);
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
/* fetch the AC table indices */
ac_y_table = get_bits(gb, 4);
ac_c_table = get_bits(gb, 4);
/* unpack the group 1 AC coefficients (coeffs 1-5) */
for (i = 1; i <= 5; i++) {
debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
i, ac_y_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
i, ac_c_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
}
/* unpack the group 2 AC coefficients (coeffs 6-14) */
for (i = 6; i <= 14; i++) {
debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
i, ac_y_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
i, ac_c_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
}
/* unpack the group 3 AC coefficients (coeffs 15-27) */
for (i = 15; i <= 27; i++) {
debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
i, ac_y_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
i, ac_c_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
}
/* unpack the group 4 AC coefficients (coeffs 28-63) */
for (i = 28; i <= 63; i++) {
debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
i, ac_y_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_y_table], i,
s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
i, ac_c_table);
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
}
return 0;
}
/*
* This function reverses the DC prediction for each coded fragment in
* the frame. Much of this function is adapted directly from the original
* VP3 source code.
*/
#define COMPATIBLE_FRAME(x) \
(compatible_frame[s->all_fragments[x].coding_method] == current_frame_type)
#define FRAME_CODED(x) (s->all_fragments[x].coding_method != MODE_COPY)
static inline int iabs (int x) { return ((x < 0) ? -x : x); }
static void reverse_dc_prediction(Vp3DecodeContext *s,
int first_fragment,
int fragment_width,
int fragment_height)
{
#define PUL 8
#define PU 4
#define PUR 2
#define PL 1
int x, y;
int i = first_fragment;
/*
* Fragment prediction groups:
*
* 32222222226
* 10000000004
* 10000000004
* 10000000004
* 10000000004
*
* Note: Groups 5 and 7 do not exist as it would mean that the
* fragment's x coordinate is both 0 and (width - 1) at the same time.
*/
int predictor_group;
short predicted_dc;
/* validity flags for the left, up-left, up, and up-right fragments */
int fl, ful, fu, fur;
/* DC values for the left, up-left, up, and up-right fragments */
int vl, vul, vu, vur;
/* indices for the left, up-left, up, and up-right fragments */
int l, ul, u, ur;
/*
* The 6 fields mean:
* 0: up-left multiplier
* 1: up multiplier
* 2: up-right multiplier
* 3: left multiplier
* 4: mask
* 5: right bit shift divisor (e.g., 7 means >>=7, a.k.a. div by 128)
*/
int predictor_transform[16][6] = {
{ 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 1, 0, 0 }, // PL
{ 0, 0, 1, 0, 0, 0 }, // PUR
{ 0, 0, 53, 75, 127, 7 }, // PUR|PL
{ 0, 1, 0, 0, 0, 0 }, // PU
{ 0, 1, 0, 1, 1, 1 }, // PU|PL
{ 0, 1, 0, 0, 0, 0 }, // PU|PUR
{ 0, 0, 53, 75, 127, 7 }, // PU|PUR|PL
{ 1, 0, 0, 0, 0, 0 }, // PUL
{ 0, 0, 0, 1, 0, 0 }, // PUL|PL
{ 1, 0, 1, 0, 1, 1 }, // PUL|PUR
{ 0, 0, 53, 75, 127, 7 }, // PUL|PUR|PL
{ 0, 1, 0, 0, 0, 0 }, // PUL|PU
{-26, 29, 0, 29, 31, 5 }, // PUL|PU|PL
{ 3, 10, 3, 0, 15, 4 }, // PUL|PU|PUR
{-26, 29, 0, 29, 31, 5 } // PUL|PU|PUR|PL
};
/* This table shows which types of blocks can use other blocks for
* prediction. For example, INTRA is the only mode in this table to
* have a frame number of 0. That means INTRA blocks can only predict
* from other INTRA blocks. There are 2 golden frame coding types;
* blocks encoding in these modes can only predict from other blocks
* that were encoded with these 1 of these 2 modes. */
unsigned char compatible_frame[8] = {
1, /* MODE_INTER_NO_MV */
0, /* MODE_INTRA */
1, /* MODE_INTER_PLUS_MV */
1, /* MODE_INTER_LAST_MV */
1, /* MODE_INTER_PRIOR_MV */
2, /* MODE_USING_GOLDEN */
2, /* MODE_GOLDEN_MV */
1 /* MODE_INTER_FOUR_MV */
};
int current_frame_type;
/* there is a last DC predictor for each of the 3 frame types */
short last_dc[3];
int transform = 0;
debug_vp3(" vp3: reversing DC prediction\n");
vul = vu = vur = vl = 0;
last_dc[0] = last_dc[1] = last_dc[2] = 0;
/* for each fragment row... */
for (y = 0; y < fragment_height; y++) {
/* for each fragment in a row... */
for (x = 0; x < fragment_width; x++, i++) {
/* reverse prediction if this block was coded */
if (s->all_fragments[i].coding_method != MODE_COPY) {
current_frame_type =
compatible_frame[s->all_fragments[i].coding_method];
predictor_group = (x == 0) + ((y == 0) << 1) +
((x + 1 == fragment_width) << 2);
debug_dc_pred(" frag %d: group %d, orig DC = %d, ",
i, predictor_group, s->all_fragments[i].coeffs[0]);
switch (predictor_group) {
case 0:
/* main body of fragments; consider all 4 possible
* fragments for prediction */
/* calculate the indices of the predicting fragments */
ul = i - fragment_width - 1;
u = i - fragment_width;
ur = i - fragment_width + 1;
l = i - 1;
/* fetch the DC values for the predicting fragments */
vul = s->all_fragments[ul].coeffs[0];
vu = s->all_fragments[u].coeffs[0];
vur = s->all_fragments[ur].coeffs[0];
vl = s->all_fragments[l].coeffs[0];
/* figure out which fragments are valid */
ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
/* decide which predictor transform to use */
transform = (fl*PL) | (fu*PU) | (ful*PUL) | (fur*PUR);
break;
case 1:
/* left column of fragments, not including top corner;
* only consider up and up-right fragments */
/* calculate the indices of the predicting fragments */
u = i - fragment_width;
ur = i - fragment_width + 1;
/* fetch the DC values for the predicting fragments */
vu = s->all_fragments[u].coeffs[0];
vur = s->all_fragments[ur].coeffs[0];
/* figure out which fragments are valid */
fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
/* decide which predictor transform to use */
transform = (fu*PU) | (fur*PUR);
break;
case 2:
case 6:
/* top row of fragments, not including top-left frag;
* only consider the left fragment for prediction */
/* calculate the indices of the predicting fragments */
l = i - 1;
/* fetch the DC values for the predicting fragments */
vl = s->all_fragments[l].coeffs[0];
/* figure out which fragments are valid */
fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
/* decide which predictor transform to use */
transform = (fl*PL);
break;
case 3:
/* top-left fragment */
/* nothing to predict from in this case */
transform = 0;
break;
case 4:
/* right column of fragments, not including top corner;
* consider up-left, up, and left fragments for
* prediction */
/* calculate the indices of the predicting fragments */
ul = i - fragment_width - 1;
u = i - fragment_width;
l = i - 1;
/* fetch the DC values for the predicting fragments */
vul = s->all_fragments[ul].coeffs[0];
vu = s->all_fragments[u].coeffs[0];
vl = s->all_fragments[l].coeffs[0];
/* figure out which fragments are valid */
ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
/* decide which predictor transform to use */
transform = (fl*PL) | (fu*PU) | (ful*PUL);
break;
}
debug_dc_pred("transform = %d, ", transform);
if (transform == 0) {
/* if there were no fragments to predict from, use last
* DC saved */
s->all_fragments[i].coeffs[0] += last_dc[current_frame_type];
debug_dc_pred("from last DC (%d) = %d\n",
current_frame_type, s->all_fragments[i].coeffs[0]);
} else {
/* apply the appropriate predictor transform */
predicted_dc =
(predictor_transform[transform][0] * vul) +
(predictor_transform[transform][1] * vu) +
(predictor_transform[transform][2] * vur) +
(predictor_transform[transform][3] * vl);
/* if there is a shift value in the transform, add
* the sign bit before the shift */
if (predictor_transform[transform][5] != 0) {
predicted_dc += ((predicted_dc >> 15) &
predictor_transform[transform][4]);
predicted_dc >>= predictor_transform[transform][5];
}
/* check for outranging on the [ul u l] and
* [ul u ur l] predictors */
if ((transform == 13) || (transform == 15)) {
if (iabs(predicted_dc - vu) > 128)
predicted_dc = vu;
else if (iabs(predicted_dc - vl) > 128)
predicted_dc = vl;
else if (iabs(predicted_dc - vul) > 128)
predicted_dc = vul;
}
/* at long last, apply the predictor */
s->all_fragments[i].coeffs[0] += predicted_dc;
debug_dc_pred("from pred DC = %d\n",
s->all_fragments[i].coeffs[0]);
}
/* save the DC */
last_dc[current_frame_type] = s->all_fragments[i].coeffs[0];
}
}
}
}
/*
* This function performs the final rendering of each fragment's data
* onto the output frame.
*/
static void render_fragments(Vp3DecodeContext *s,
int first_fragment,
int width,
int height,
int plane /* 0 = Y, 1 = U, 2 = V */)
{
int x, y;
int m, n;
int i = first_fragment;
int j;
int16_t *dequantizer;
DCTELEM dequant_block[64];
DCTELEM dequant_block_permuted[64];
unsigned char *output_plane;
unsigned char *last_plane;
unsigned char *golden_plane;
int stride;
int motion_x, motion_y;
int upper_motion_limit, lower_motion_limit;
int motion_halfpel_index;
unsigned int motion_source;
debug_vp3(" vp3: rendering final fragments for %s\n",
(plane == 0) ? "Y plane" : (plane == 1) ? "U plane" : "V plane");
/* set up plane-specific parameters */
if (plane == 0) {
dequantizer = s->intra_y_dequant;
output_plane = s->current_frame.data[0];
last_plane = s->last_frame.data[0];
golden_plane = s->golden_frame.data[0];
stride = -s->current_frame.linesize[0];
upper_motion_limit = 7 * s->current_frame.linesize[0];
lower_motion_limit = height * s->current_frame.linesize[0] + width - 8;
} else if (plane == 1) {
dequantizer = s->intra_c_dequant;
output_plane = s->current_frame.data[1];
last_plane = s->last_frame.data[1];
golden_plane = s->golden_frame.data[1];
stride = -s->current_frame.linesize[1];
upper_motion_limit = 7 * s->current_frame.linesize[1];
lower_motion_limit = height * s->current_frame.linesize[1] + width - 8;
} else {
dequantizer = s->intra_c_dequant;
output_plane = s->current_frame.data[2];
last_plane = s->last_frame.data[2];
golden_plane = s->golden_frame.data[2];
stride = -s->current_frame.linesize[2];
upper_motion_limit = 7 * s->current_frame.linesize[2];
lower_motion_limit = height * s->current_frame.linesize[2] + width - 8;
}
/* for each fragment row... */
for (y = 0; y < height; y += 8) {
/* for each fragment in a row... */
for (x = 0; x < width; x += 8, i++) {
if ((i < 0) || (i >= s->fragment_count)) {
printf (" vp3:render_fragments(): bad fragment number (%d)\n", i);
return;
}
/* transform if this block was coded */
if (s->all_fragments[i].coding_method != MODE_COPY) {
/* sort out the motion vector */
motion_x = s->all_fragments[i].motion_x;
motion_y = s->all_fragments[i].motion_y;
motion_halfpel_index = s->all_fragments[i].motion_halfpel_index;
motion_source = s->all_fragments[i].first_pixel;
motion_source += motion_x;
motion_source += (motion_y * stride);
/* if the are any problems with a motion vector, refuse
* to render the block */
if ((motion_source < upper_motion_limit) ||
(motion_source > lower_motion_limit)) {
// printf (" vp3: help! motion source (%d) out of range (%d..%d)\n",
// motion_source, upper_motion_limit, lower_motion_limit);
continue;
}
/* first, take care of copying a block from either the
* previous or the golden frame */
if ((s->all_fragments[i].coding_method == MODE_USING_GOLDEN) ||
(s->all_fragments[i].coding_method == MODE_GOLDEN_MV)) {
s->dsp.put_pixels_tab[1][motion_halfpel_index](
output_plane + s->all_fragments[i].first_pixel,
golden_plane + motion_source,
stride, 8);
} else
if (s->all_fragments[i].coding_method != MODE_INTRA) {
s->dsp.put_pixels_tab[1][motion_halfpel_index](
output_plane + s->all_fragments[i].first_pixel,
last_plane + motion_source,
stride, 8);
}
/* dequantize the DCT coefficients */
debug_idct("fragment %d, coding mode %d, DC = %d, dequant = %d:\n",
i, s->all_fragments[i].coding_method,
s->all_fragments[i].coeffs[0], dequantizer[0]);
for (j = 0; j < 64; j++)
dequant_block[dezigzag_index[j]] =
s->all_fragments[i].coeffs[j] *
dequantizer[j];
for (j = 0; j < 64; j++)
dequant_block_permuted[s->dsp.idct_permutation[j]] =
dequant_block[j];
debug_idct("dequantized block:\n");
for (m = 0; m < 8; m++) {
for (n = 0; n < 8; n++) {
debug_idct(" %5d", dequant_block[m * 8 + n]);
}
debug_idct("\n");
}
debug_idct("\n");
/* invert DCT and place (or add) in final output */
if (s->all_fragments[i].coding_method == MODE_INTRA) {
dequant_block_permuted[0] += 1024;
s->dsp.idct_put(
output_plane + s->all_fragments[i].first_pixel,
stride, dequant_block_permuted);
} else {
s->dsp.idct_add(
output_plane + s->all_fragments[i].first_pixel,
stride, dequant_block_permuted);
}
debug_idct("block after idct_%s():\n",
(s->all_fragments[i].coding_method == MODE_INTRA)?
"put" : "add");
for (m = 0; m < 8; m++) {
for (n = 0; n < 8; n++) {
debug_idct(" %3d", *(output_plane +
s->all_fragments[i].first_pixel + (m * stride + n)));
}
debug_idct("\n");
}
debug_idct("\n");
} else {
/* copy directly from the previous frame */
s->dsp.put_pixels_tab[1][0](
output_plane + s->all_fragments[i].first_pixel,
last_plane + s->all_fragments[i].first_pixel,
stride, 8);
}
}
}
emms_c();
}
/*
* This function computes the first pixel addresses for each fragment.
* This function needs to be invoked after the first frame is allocated
* so that it has access to the plane strides.
*/
static void vp3_calculate_pixel_addresses(Vp3DecodeContext *s)
{
int i, x, y;
/* figure out the first pixel addresses for each of the fragments */
/* Y plane */
i = 0;
for (y = s->fragment_height; y > 0; y--) {
for (x = 0; x < s->fragment_width; x++) {
s->all_fragments[i++].first_pixel =
s->golden_frame.linesize[0] * y * FRAGMENT_PIXELS -
s->golden_frame.linesize[0] +
x * FRAGMENT_PIXELS;
debug_init(" fragment %d, first pixel @ %d\n",
i-1, s->all_fragments[i-1].first_pixel);
}
}
/* U plane */
i = s->u_fragment_start;
for (y = s->fragment_height / 2; y > 0; y--) {
for (x = 0; x < s->fragment_width / 2; x++) {
s->all_fragments[i++].first_pixel =
s->golden_frame.linesize[1] * y * FRAGMENT_PIXELS -
s->golden_frame.linesize[1] +
x * FRAGMENT_PIXELS;
debug_init(" fragment %d, first pixel @ %d\n",
i-1, s->all_fragments[i-1].first_pixel);
}
}
/* V plane */
i = s->v_fragment_start;
for (y = s->fragment_height / 2; y > 0; y--) {
for (x = 0; x < s->fragment_width / 2; x++) {
s->all_fragments[i++].first_pixel =
s->golden_frame.linesize[2] * y * FRAGMENT_PIXELS -
s->golden_frame.linesize[2] +
x * FRAGMENT_PIXELS;
debug_init(" fragment %d, first pixel @ %d\n",
i-1, s->all_fragments[i-1].first_pixel);
}
}
}
/*
* This is the ffmpeg/libavcodec API init function.
*/
static int vp3_decode_init(AVCodecContext *avctx)
{
Vp3DecodeContext *s = avctx->priv_data;
int i;
int c_width;
int c_height;
int y_superblock_count;
int c_superblock_count;
s->avctx = avctx;
s->width = avctx->width;
s->height = avctx->height;
avctx->pix_fmt = PIX_FMT_YUV420P;
avctx->has_b_frames = 0;
dsputil_init(&s->dsp, avctx);
/* initialize to an impossible value which will force a recalculation
* in the first frame decode */
s->quality_index = -1;
s->y_superblock_width = (s->width + 31) / 32;
s->y_superblock_height = (s->height + 31) / 32;
y_superblock_count = s->y_superblock_width * s->y_superblock_height;
/* work out the dimensions for the C planes */
c_width = s->width / 2;
c_height = s->height / 2;
s->c_superblock_width = (c_width + 31) / 32;
s->c_superblock_height = (c_height + 31) / 32;
c_superblock_count = s->c_superblock_width * s->c_superblock_height;
s->superblock_count = y_superblock_count + (c_superblock_count * 2);
s->u_superblock_start = y_superblock_count;
s->v_superblock_start = s->u_superblock_start + c_superblock_count;
s->superblock_coding = av_malloc(s->superblock_count);
s->macroblock_width = (s->width + 15) / 16;
s->macroblock_height = (s->height + 15) / 16;
s->macroblock_count = s->macroblock_width * s->macroblock_height;
s->fragment_width = s->width / FRAGMENT_PIXELS;
s->fragment_height = s->height / FRAGMENT_PIXELS;
/* fragment count covers all 8x8 blocks for all 3 planes */
s->fragment_count = s->fragment_width * s->fragment_height * 3 / 2;
s->u_fragment_start = s->fragment_width * s->fragment_height;
s->v_fragment_start = s->fragment_width * s->fragment_height * 5 / 4;
debug_init(" Y plane: %d x %d\n", s->width, s->height);
debug_init(" C plane: %d x %d\n", c_width, c_height);
debug_init(" Y superblocks: %d x %d, %d total\n",
s->y_superblock_width, s->y_superblock_height, y_superblock_count);
debug_init(" C superblocks: %d x %d, %d total\n",
s->c_superblock_width, s->c_superblock_height, c_superblock_count);
debug_init(" total superblocks = %d, U starts @ %d, V starts @ %d\n",
s->superblock_count, s->u_superblock_start, s->v_superblock_start);
debug_init(" macroblocks: %d x %d, %d total\n",
s->macroblock_width, s->macroblock_height, s->macroblock_count);
debug_init(" %d fragments, %d x %d, u starts @ %d, v starts @ %d\n",
s->fragment_count,
s->fragment_width,
s->fragment_height,
s->u_fragment_start,
s->v_fragment_start);
s->all_fragments = av_malloc(s->fragment_count * sizeof(Vp3Fragment));
s->coded_fragment_list = av_malloc(s->fragment_count * sizeof(int));
s->pixel_addresses_inited = 0;
/* init VLC tables */
for (i = 0; i < 16; i++) {
/* DC histograms */
init_vlc(&s->dc_vlc[i], 5, 32,
&dc_bias[i][0][1], 4, 2,
&dc_bias[i][0][0], 4, 2);
/* group 1 AC histograms */
init_vlc(&s->ac_vlc_1[i], 5, 32,
&ac_bias_0[i][0][1], 4, 2,
&ac_bias_0[i][0][0], 4, 2);
/* group 2 AC histograms */
init_vlc(&s->ac_vlc_2[i], 5, 32,
&ac_bias_1[i][0][1], 4, 2,
&ac_bias_1[i][0][0], 4, 2);
/* group 3 AC histograms */
init_vlc(&s->ac_vlc_3[i], 5, 32,
&ac_bias_2[i][0][1], 4, 2,
&ac_bias_2[i][0][0], 4, 2);
/* group 4 AC histograms */
init_vlc(&s->ac_vlc_4[i], 5, 32,
&ac_bias_3[i][0][1], 4, 2,
&ac_bias_3[i][0][0], 4, 2);
}
/* build quantization zigzag table */
for (i = 0; i < 64; i++)
zigzag_index[dezigzag_index[i]] = i;
/* work out the block mapping tables */
s->superblock_fragments = av_malloc(s->superblock_count * 16 * sizeof(int));
s->superblock_macroblocks = av_malloc(s->superblock_count * 4 * sizeof(int));
s->macroblock_fragments = av_malloc(s->macroblock_count * 6 * sizeof(int));
s->macroblock_coding = av_malloc(s->macroblock_count + 1);
init_block_mapping(s);
for (i = 0; i < 3; i++) {
s->current_frame.data[i] = NULL;
s->last_frame.data[i] = NULL;
s->golden_frame.data[i] = NULL;
}
return 0;
}
/*
* This is the ffmpeg/libavcodec API frame decode function.
*/
static int vp3_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
Vp3DecodeContext *s = avctx->priv_data;
GetBitContext gb;
static int counter = 0;
*data_size = 0;
init_get_bits(&gb, buf, buf_size * 8);
s->keyframe = get_bits(&gb, 1);
s->keyframe ^= 1;
skip_bits(&gb, 1);
s->last_quality_index = s->quality_index;
s->quality_index = get_bits(&gb, 6);
if (s->quality_index != s->last_quality_index)
init_dequantizer(s);
debug_vp3(" VP3 frame #%d: Q index = %d", counter, s->quality_index);
counter++;
if (s->keyframe) {
debug_vp3(", keyframe\n");
/* skip the other 2 header bytes for now */
skip_bits(&gb, 16);
if (s->last_frame.data[0] == s->golden_frame.data[0]) {
if (s->golden_frame.data[0])
avctx->release_buffer(avctx, &s->golden_frame);
} else {
if (s->golden_frame.data[0])
avctx->release_buffer(avctx, &s->golden_frame);
if (s->last_frame.data[0])
avctx->release_buffer(avctx, &s->last_frame);
}
s->golden_frame.reference = 0;
if(avctx->get_buffer(avctx, &s->golden_frame) < 0) {
printf("vp3: get_buffer() failed\n");
return -1;
}
/* golden frame is also the current frame */
memcpy(&s->current_frame, &s->golden_frame, sizeof(AVFrame));
/* time to figure out pixel addresses? */
if (!s->pixel_addresses_inited)
vp3_calculate_pixel_addresses(s);
} else {
debug_vp3("\n");
/* allocate a new current frame */
s->current_frame.reference = 0;
if(avctx->get_buffer(avctx, &s->current_frame) < 0) {
printf("vp3: get_buffer() failed\n");
return -1;
}
}
init_frame(s, &gb);
#if KEYFRAMES_ONLY
if (!s->keyframe) {
memcpy(s->current_frame.data[0], s->golden_frame.data[0],
s->current_frame.linesize[0] * s->height);
memcpy(s->current_frame.data[1], s->golden_frame.data[1],
s->current_frame.linesize[1] * s->height / 2);
memcpy(s->current_frame.data[2], s->golden_frame.data[2],
s->current_frame.linesize[2] * s->height / 2);
} else {
#endif
if (unpack_superblocks(s, &gb) ||
unpack_modes(s, &gb) ||
unpack_vectors(s, &gb) ||
unpack_dct_coeffs(s, &gb)) {
printf(" vp3: could not decode frame\n");
return -1;
}
reverse_dc_prediction(s, 0, s->fragment_width, s->fragment_height);
reverse_dc_prediction(s, s->u_fragment_start,
s->fragment_width / 2, s->fragment_height / 2);
reverse_dc_prediction(s, s->v_fragment_start,
s->fragment_width / 2, s->fragment_height / 2);
render_fragments(s, 0, s->width, s->height, 0);
render_fragments(s, s->u_fragment_start, s->width / 2, s->height / 2, 1);
render_fragments(s, s->v_fragment_start, s->width / 2, s->height / 2, 2);
#if KEYFRAMES_ONLY
}
#endif
*data_size=sizeof(AVFrame);
*(AVFrame*)data= s->current_frame;
/* release the last frame, if it is allocated and if it is not the
* golden frame */
if ((s->last_frame.data[0]) &&
(s->last_frame.data[0] != s->golden_frame.data[0]))
avctx->release_buffer(avctx, &s->last_frame);
/* shuffle frames (last = current) */
memcpy(&s->last_frame, &s->current_frame, sizeof(AVFrame));
return buf_size;
}
/*
* This is the ffmpeg/libavcodec API module cleanup function.
*/
static int vp3_decode_end(AVCodecContext *avctx)
{
Vp3DecodeContext *s = avctx->priv_data;
av_free(s->all_fragments);
av_free(s->coded_fragment_list);
av_free(s->superblock_fragments);
av_free(s->superblock_macroblocks);
av_free(s->macroblock_fragments);
av_free(s->macroblock_coding);
/* release all frames */
if (s->golden_frame.data[0])
avctx->release_buffer(avctx, &s->golden_frame);
if (s->last_frame.data[0])
avctx->release_buffer(avctx, &s->last_frame);
/* no need to release the current_frame since it will always be pointing
* to the same frame as either the golden or last frame */
return 0;
}
AVCodec vp3_decoder = {
"vp3",
CODEC_TYPE_VIDEO,
CODEC_ID_VP3,
sizeof(Vp3DecodeContext),
vp3_decode_init,
NULL,
vp3_decode_end,
vp3_decode_frame,
0,
NULL
};